The present invention relates to apparatus for controlling the liquid level in tanks and, in particular, to such apparatus for use in toilet flush tanks.
Various types of valves have utilized a flexible, resilient pinch tube as the valve member, which is controlled by a lever-type actuator engageable with the outside of the tube to pinch it closed. Such a valve is disclosed, for example, in U.S. Pat. No. 5,402,823. Pinch tube valves have heretofore been used as toilet level control valves, for example in U.S. Pat. No. 3,996,960. However, such valves have typically utilized a ball cock mechanism wherein the actuator is coupled by a long arm to a float. Such ball cock devices require considerable lateral space in the tank to accommodate the float and its arm.
It is also known to utilize flush tank level control valves with floats which encircle and ride up and down along an upright fill tube, so as to occupy less space in the tank. Such valves have heretofore utilized a poppet-type valve mechanism, which is of relatively complex construction.
It is also known to provide snap-action shutoff of flush tank level control valves by providing means for resiliently arresting the upward movement of the float short of the closed-valve position, the arresting mechanism yielding when the buoyancy force of the rising water level on the float reaches a sufficient value, for suddenly closing the valve. But such mechanisms heretofore have been relatively complex and have not been utilized with pinch tube-type valves.